1. Field of the Invention
The present invention relates to motor and pedal driven bicycles, and more particularly to a motor and pedal driven bicycle that can run with a wheel driving motor powered by a battery without pedaling (motor running mode), said bicycle also being capable of running by pedaling with the motor brought to a halt (pedal running mode), said bicycle also being capable of running by simultaneously pedaling and operating the motor used as an auxiliary power source (motor-assisted pedal running mode).
2. Description of the Prior Art
A conventionally known motor and pedal driven bicycle a motor driving unit essentially comprising a housing (casing) rotatably supported on a rear wheel axle (hub spindle) and is provided with spokes of the rear wheel, and a wheel driving motor mounted on the rear wheel axle in the housing in such a manner that the motor encloses the rear wheel axle (Japanese Published Examined Patent Application (Tokkyo Koho) No. SHO 53-10733/1978).
This kind of motor and pedal driven bicycle incorporates within the housing of the motor driving unit a speed reducer having a plurality of reducing gears in addition to a wheel driving motor. Further, the final step of the reducing gears in the speed reducer is engaged with the housing, thereby transmitting to the housing a revolution of the motor reduced with the speed reducer.
Such construction of the bicycle may cause a safety problem because it makes it impossible for users to check engagement of the speed reducer, namely engagement between the reducing gears therein and between the gears and the housing after the motor and the speed reducer has been incorporated in a predetermined location of the housing. In addition, such bicycle suffers from a drawback of inferior assemblage of the housing as a whole because it has been necessary to arrange the motor and the speed reducer in the housing to eliminate the need of checking the above engagement.